Hi,
I am new to solar and I was looking at buying some used panels to add to my system. I have a Growatt SPF 5000 US. It will handle 6000 watts at 450 volts Maximum with a max of 100 amps on the charging circuit. I am looking at hooking up 27 - 225 watt used panels in three strings of 9 panels for a total wattage of 2025 watts per string. The system would produce a total of 6075 watts at 331.92 volts with an open circuit amperage of 24.81 amps. I was going to combine these in a combiner box and run the PV back through 10awg wires in conduit to the inverter with 15 amp fuses on each positive wire on the string. When I went to order the panels I was told that the Growatt can only handle two strings of panels and if I add the third string that I won't see any gain from from it.
Panel specs are as follows: output = 225 watts, open circuit voltage (VOC) = 36.88v, Short circuit current (ISC) = 8.27a
Is this true? This doesn't seem right to me, but I am just a newbie so I am asking the experts here. If this IS true I may switch up horses to another used panel that is 250 watts and look at making two strings of 11 panels.
Panel specs Rated Power: 250W, Open circuit voltage (VOC): 37.6 V, Short circuit current (ISC): 8.85 A,
Two strings of 12 would be 6000 watts, 17.7 amps but 451.2 volts, Over my 450 volt maximum.
So I would be looking at 2 strings at 413.6 volts per string and 2750 watts per string with 8.85 ams per string.
Total would be 5,500 watts, 413 volts and 17.7 amps. That puts my amps pretty close to max on a very cold Missouri day.....
So can I do three strings, or do I need to focus on two? Thanks, Daniel
I am new to solar and I was looking at buying some used panels to add to my system. I have a Growatt SPF 5000 US. It will handle 6000 watts at 450 volts Maximum with a max of 100 amps on the charging circuit. I am looking at hooking up 27 - 225 watt used panels in three strings of 9 panels for a total wattage of 2025 watts per string. The system would produce a total of 6075 watts at 331.92 volts with an open circuit amperage of 24.81 amps. I was going to combine these in a combiner box and run the PV back through 10awg wires in conduit to the inverter with 15 amp fuses on each positive wire on the string. When I went to order the panels I was told that the Growatt can only handle two strings of panels and if I add the third string that I won't see any gain from from it.
Panel specs are as follows: output = 225 watts, open circuit voltage (VOC) = 36.88v, Short circuit current (ISC) = 8.27a
Is this true? This doesn't seem right to me, but I am just a newbie so I am asking the experts here. If this IS true I may switch up horses to another used panel that is 250 watts and look at making two strings of 11 panels.
Panel specs Rated Power: 250W, Open circuit voltage (VOC): 37.6 V, Short circuit current (ISC): 8.85 A,
Two strings of 12 would be 6000 watts, 17.7 amps but 451.2 volts, Over my 450 volt maximum.
So I would be looking at 2 strings at 413.6 volts per string and 2750 watts per string with 8.85 ams per string.
Total would be 5,500 watts, 413 volts and 17.7 amps. That puts my amps pretty close to max on a very cold Missouri day.....
So can I do three strings, or do I need to focus on two? Thanks, Daniel
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